GO curators for mouse genes have assigned the following annotations to the gene product of Hoxd4. (This text reflects annotations as of Tuesday, May 26, 2015.) Summary from NCBI RefSeq

[Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene belongs to the homeobox family of genes. The homeobox genes encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms. Mammals possess four similar homeobox gene clusters, HOXA, HOXB, HOXC and HOXD, located on different chromosomes, consisting of 9 to 11 genes arranged in tandem. This gene is one of several homeobox HOXD genes located at 2q31-2q37 chromosome regions. Deletions that removed the entire HOXD gene cluster or 5' end of this cluster have been associated with severe limb and genital abnormalities. The protein encoded by this gene may play a role in determining positional values in developing limb buds. Alternatively spliced variants have been described but their full length nature has not been determined. [provided by RefSeq, Jul 2008]Summary text based on GO annotations supported by experimental evidence in mouse

Researchers have inferred from direct assay, that the gene product of Hoxd4

Horan GS et al. (1995) Compound mutants for the paralogous hoxa-4, hoxb-4, and hoxd-4 genes show more complete homeotic transformations and a dose-dependent increase in the number of vertebrae transformed. Genes Dev, 9:1667-77. (PubMed:7628700)